Lesson 2: Keyboard Remote

What does it mean for a robot to be autonomous or remote controlled? An autonomous robot is a robot that can perform an action automatically without being directly controlled by a person. These robots are usually able to use their sensors to gain information and make decisions! A remote controlled robot is a robot that has a person directly controlling what the robot does with a remote controller. 

Try taking the “Autonomous or Not?” quiz below. You will see a a bunch of different robots and answer which you think is an autonomous robot or a remote controlled robot!

Pseudocode is a helpful way to keep your code organized and it can help with planning big projects like a keyboard remote! Here is an example of how pseudocode might be used.

if I press "w"
then my drone will fly up towards the ceiling

Can you think of any other buttons we might need to build a keyboard remote? What flight direction do you think your drone should go for each button?

Now we will build our keyboard remote!

First, you will set up the structure of the program to handle roll, pitch, yaw, and throttle. Since there are positive and negative values for each flight direction, there are 8 total possible commands plus the spacebar for emergency stop.

In this example, the following keyboard commands will be used, but you can change the values to whatever you want.

• W/S- Positive/Negative throttle
• D/A- Positive/Negative Yaw
• Up/Down- Positive/Negative Pitch
• Right/Left- Positive/Negative

Space- Emergency stop

Think about how you should program your if statements. Remember that if and else-if are useful when you only want to execute one of those commands. However, using one if statement and 7 if-else statements means you can only fly in one direction at a time! To be able to fly in more than one direction you need to group your if statements into roll, pitch, yaw, and throttle. For example:

• If W is pressed, set throttle to 75
• Else if S is pressed, set throttle to -75
• Else, set throttle to 0.

The else statement is very important. It resets the value of throttle to zero whenever neither key is pressed.